System for the continuous production of building elements

ABSTRACT

Plant for the continuous production of building elements which consist of two parallel flat grid meshes made from welded longitudinal and transverse wires, of straight web wires holding the grid meshes at a predetermined mutual spacing and of an insulating body which is arranged between the grid meshes and through which the web wires penetrate, with a production channel (2), on both sides of which supply reels (3, 3&#39;) and straightening devices (5, 5&#39;), each for an endless grid sheet (G, G&#39;) standing on edge, and push-in devices (7, 7&#39;) are provided for drawing off the grid sheets in steps and for introducing these into grid-sheet lead devices (14, 14&#39;), two cutting devices (11, 11&#39;) for severing grid meshes (M, M&#39;) of predetermined length being arranged upstream of the lead devices, and the grid meshes being capable of being advanced in the lead devices and in the production channel in steps to web-wire feeding and cutting devices (26, 26&#39;) by means of a grid-mesh conveying device (18) and downstream welding devices (30, 30&#39;) being capable of being advanced for the simultaneous welding of the two ends of all the web wires (S) to corresponding longitudinal wires (L, L&#39;) of the grid meshes, furthermore an insulating-body guide device (22) and an insulating-body conveying device (24) being provided for advancing the insulating bodies in steps, synchronously with the grid meshes and a building-element conveying device (32) being provided for conveying the building elements in steps to web-wire trimming devices (35, 35&#39;) and for conveying the building elements out of the production channel, and the push-in devices and all the conveying devices, coupled to one another, being capable of being driven jointly by means of drive shafts (38, 38&#39;).

The invention relates to a plant for the continuous production ofbuilding elements which consist of two parallel flat grid meshes madefrom intersecting longitudinal and transverse wires welded to oneanother at the intersection points, of straight web wires holding thegrid meshes at a predetermined mutual spacing and of an insulating bodywhich is arranged between the grid meshes and through which the webwires penetrate, with a production channel, with two supply reels,arranged on both sides of the production channel, and downstreamstraightening devices, each for a grid sheet, with two curved leaddevices opening tangentially on opposite longitudinal sides of theproduction channel, with an insulating-body guide device arrangedbetween the two lead devices, with at least one group, arrangedlaterally of the production channel, of web-wire supply reels andweb-wire feeding and cutting devices, with web-wire welding deviceswhich are arranged on both sides of the production channel and whichhave a transformer and flexible electrical leads from the secondaryoutputs of the transformer to jaws of welding tongs pivotable into thegrid-mesh planes, and with web-wire trimming devices, each for severinga projecting length of web wire.

A plant of this generic type is known from Austrian Patent Specification372,868. In this plant, first of all, two grid sheets are brought into aparallel position at a mutual spacing corresponding to the desiredthickness of the building element to be produced. An insulating board isinserted into the interspace between the grid sheets and with a spacingfrom each grid sheet. A plurality of web wires are guided in verticalrows one above the other from the side, from wire-supply reels, throughone of the two grid sheets into the interspace between the grid sheetsand through the insulating board, in such a way that each web wire comesto rest with each of its ends near one grid wire of the two grid sheets.The front ends of the web wires are welded to the corresponding gridwires of the one grid sheet and the web wires are severed from the wiresupply. In a subsequent work step, in a further web-wire welding devicethe severed ends of the web wires are welded to the corresponding gridwires of the other grid sheet.

The welding devices used in the known plant consist essentially of atransformer, of flexible electrical leads, connecting the secondaryoutputs of the transformer to electrode holders and of electrodes. Theelectrode holders form jaws of welding tongs and are pivotable into thegrid-mesh plane. In a subsequent work step, the laterally protrudingprojecting lengths of the web-wire ends are severed by the pivotablymounted trimming shears. One jaw of each trimming shear serves as anabutment for a grid wire of the grid meshes of the element, whilst theother jaw of each trimming shear acts as a knife which shears off theprojecting length of web wire in each case in the direction of the gridwire retained by the jaw. Finally, building elements of appropriatelength are separated.

A disadvantage of the known plant is that only a joint change of theshoot-in angles of the two rows of web wires is possible, and that anadditional welding station is necessary in the case of large spacingsbetween adjacent rows of web wires in the shoot-in region of the webwires. Another disadvantage is that work is carried out with individualindependent electrode holders and that a particular trimming shear isrequired for each projecting length of web wire, whilst all theelectrode holders and all the trimming shears have to be activatedseparately. A further disadvantage is, finally, that the cutting devicesfor severing the grid sheets of the already finished building elementinvolve an extremely high outlay.

The object of the invention is to provide a plant of a type specified inthe introduction, which avoids the disadvantages of the known plant andwhich, moreover, makes it possible, in a continuous productionoperation, to produce building elements with different arrangements ofweb wires and rows of web wires in the building element and with varioustypes of grid meshes. The object of the invention is, furthermore, toprovide a plant which makes it possible, in one welding operation, toweld the ends of all the web wires of a row simultaneously to thelongitudinal wires of at least one grid mesh and to sever a plurality ofprojecting lengths of web wire simultaneously in one cutting operation.

The plant according to the invention is characterized in that a push-indevice for drawing off in steps an endless grid sheet standing on edgefrom at least one supply reel, and for introducing the grid sheet intothe lead devices is arranged on each of the two sides of the productionchannel, in that two cutting devices for severing grid meshes ofpredetermined length from the endless grid sheets are provided upstreamof the lead devices, the grid meshes being capable of being advanced insteps in the lead devices and in the production channel by means of agrid-mesh conveying device, in that an insulating-body conveying deviceextending over the insulating-body guide device and the productionchannel is provided for advancing in steps, synchronously with the gridmeshes, at least partially dimensionally stable insulating bodiesintended for fixing the web wires, in that the feeding and cuttingdevices for equipping the insulating body with web wires and downstreamwelding devices for the simultaneous welding of the two ends of all theweb wires to corresponding longitudinal wires of the grid meshes areprovided in the effective range of the grid-mesh conveying device, inthat, by means of a building-element conveying device, the buildingelements can in steps and successively be fed to the web-wire trimmingdevices and be conveyed out of the production channel, and in that thepush-in devices and all the conveying devices, coupled to one another,can be driven jointly by means of drive shafts.

This construction makes it possible with high operating reliability andeconomically to obtain the continuous production of building elements ofdiffering design, that is to say a highly flexible mode of operation.

According to a preferred embodiment of the invention, a delivery deviceis provided for the at least single-track feed of insulating bodies cutto length and/or of an endless insulating-body sheet into the guidedevice and a cutting device for severing insulating bodies ofpredetermined length from the insulating-body sheet is provided in theexit region of the guide device.

According to a further feature of the invention, provision is made forthe grid-mesh conveying device and the building-element conveying deviceeach to have at least two pairs of advancing elements or conveyingelements, the individual elements of all the pairs being locatedopposite one another on both sides of the production channel. At thesame time, preferably, each advancing element, each conveying elementand each grid-sheet push-in device has a shaft inclined relative to thevertical direction and possessing at least two transport discs providedwith a plurality of grid-engagement recesses.

According to the invention, the web-wire feeding and cutting devices arepivotable in order to vary the shoot-in angles of the web wires.

A development of the invention has the features that there is providedfor each side face of the building element to be produced at least onewelding device provided with a plurality of welding tongs, for thesimultaneous welding of, in each case, one end of a plurality ofstraight web wires, arranged one above the other at a mutual spacing inat least one row, to the horizontally extending longitudinal wires of agrid mesh, the welding tongs being designed as two-armed pivotable lowerand upper welding-tong levers which cooperate in pairs and of which theends facing the grid meshes and pivotable into the grid-mesh planes havewelding electrodes for welding at least one web wire to one longitudinalwire of the grid mesh.

Further features and advantages of the invention are explained in moredetail below by means of exemplary embodiments with reference to thedrawings. In these:

FIG. 1 shows a diagrammatic top view of a plant according to theinvention;

FIG. 2 shows a diagrammatic side view of a grid-mesh conveying device;

FIGS. 3a and 3b show different types of transport discs;

FIG. 4 shows a diagrammatic vertical section through a web-wire weldingdevice of the plant according to the invention, the welding devicerepresented in the left-hand half of the drawing being shown in itsinitial position and the welding device represented in the right-handhalf of the drawing being shown in its welding position;

FIG. 5 shows a diagrammatic horizontal section through the web-wirewelding device;

FIG. 6 shows a diagrammatic vertical section through trimming devices ofthe plant, the trimming device represented in the left-hand half of thedrawing being shown in its initial position and the trimming devicerepresented in the right-hand half of the drawing being shown in itsposition after the cut;

FIG. 7 shows a diagrammatic horizontal section through the trimmingdevices and FIG. 8 a diagrammatic top view of parts of a furtherexemplary embodiment of a plant according to the invention.

The plant according to the invention illustrated in FIG. 1 serves forthe production of a building element B consisting of two parallel flatgrid meshes M, M' made from intersecting longitudinal and transversewires L, L' and Q, Q' welded to one another at the intersection points,of straight web wires S which hold the two grid meshes M, M' atpredetermined mutual spacing and which are each welded at each end to awire of the two grid meshes M, M', and of an at least partiallydimensionally stable insulating body I, for example an insulating boardmade of plastic, arranged between the grid meshes M, M' and with apredetermined spacing from these.

The plant has a basic frame 1, on which a horizontal production channel2, merely indicated diagrammatically, is arranged preferably centrally.Two grid sheets G and G' standing on edge are drawn off according to thearrows P1 and P1' from two supply reels 3, 3', the mutual spacings ofthe longitudinal wires L; L' and of the transverse wires Q; Q' of eachgrid sheet G; G' relative to one another, that is to say the so-calledlongitudinal-wire and transverse-wire divisions, and the width of eachgrid sheet G; G' being freely selectable within specific ranges.

By way of a grid-sheet guide 4; 4', each grid sheet G; G' passes into astraightening device 5; 5' which consists in each case of a plurality ofstraightening rollers 6; 6' which are offset relative to one another andwhich straighten each grid sheet. Each straightening device 5; 5' has,on its entry side, a grid-sheet feeding device 7; 7' which consists ineach case of a take-up roller 8; 8' and of a driving roller 9; 9'cooperating with the take-up roller 8; 8', each driving roller 9; 9'being capable of being brought by pivoting according to the double arrowP2; P2' either into or out of engagement with the take-up roller 8; 8'.The grid-sheet feeding devices 7, 7' have the function of feeding thegrid sheets G, G' for further processing to downstream grid-sheetpush-in devices 10, 10' in the direction of the arrows P1; P1' or ofconveying grid-sheet residues no longer required after the completion ofproduction out of the straightening devices 5, 5' in the oppositedirection to the arrows P1; P1'.

Each grid-sheet push-in device 10; 10' is pivotable according to thedouble arrow P3; P3' between a working position, in which it is inengagement with the grid sheet G; G' to be pushed in, and a position ofrest, in which it is out of engagement with the grid sheet G; G'. Bymeans of the grid-sheet push-in devices 10, 10', the design of which isdescribed later, the grid sheets G, G' are fed in steps to mesh shears11, 11' which each have essentially a cutting bar 12; 12' and a knifebar 13, 13' and which sever grid meshes M, M' of predetermined lengthfrom endless grid sheets.

In the example shown, the mesh shears 11, 11' work in such a way thatthey execute a severing cut and consequently sever successive gridmeshes M, M' continuously from the grid sheets G, G'. Within the scopeof the invention, however, it is also possible to design and activatethe mesh shears 11, 11' in such a way that they execute a trimming cuton the longitudinal wires and, in one or in two cutting operations, cutout from the grid sheets G, G' a selectable portion, of which the lengthin the direction of advance corresponds preferably to thetransverse-wire division or to an integral multiple of thetransverse-wire division.

By means of slightly curved lead devices 14, 14' which only elasticallydeform the straightened grid meshes M, M' and open tangentially onopposite longitudinal sides of the production channel 2 and whichconsist, for example, of a plurality of arcuate battens arranged oneabove the other and are fastened to the basic frame 1 by means ofbrackets 15, 15' and mountings 16, 16', the grid meshes M, M' are ledinto the production channel 2 in such a way that they come into aposition parallel to one another there, with a mutual spacing whichcorresponds to the desired thickness of the building element B to beproduced. In the production channel 2, the two grid meshes M, M' arereliably guided over their entire width and always maintained exactly atthis specific spacing by means of distancing elements 17, 17', merelyindicated diagrammatically, which consist, for example, of distanceplates and of a plurality of distance guides arranged one above theother in the vertical direction.

By means of a grid-mesh conveying device 18 which has essentially twopairs of advancing elements 19, 19' and 20, 20' located opposite oneanother and arranged on both sides of the production channel 2, the twogrid meshes M, M' are conveyed in steps in the lead devices 14, 14' andin the production direction P4 along the production channel 2 to thedownstream processing stations. The first pair of advancing elements 19,19' is arranged in the parallel exit region of the lead devices 14, 14'.The spacing of the first pair of advancing elements 19, 19' from themesh shears 11, 11' and the spacing of the two pairs of advancingelements 19, 19' and 20, 20' from one another must be smaller than thesmallest length of the grid meshes M, M' intended for the production ofthe building element B, in order to guarantee a reliable furtherconveyance of the grid meshes M, M' by the grid-mesh conveying device18.

The preferably board-like individual insulating bodies I are fed by adelivery device 21 in the direction of the arrow P5 to a guide device 22which forms the entry side of the production channel 2 and which isfastened to the basic frame 1 by means of a fastening plate 23. Theguide device 22 is designed in such a way that the insulating body I isguided reliably both in the vertical direction and in its positionrelative to the two grid meshes M, M' and at a predetermined spacingfrom these. The length and width of the insulating body I are preferablyidentical to the length and width of the grid meshes M, M' respectively.

In the entry region of the guide device 22, the insulating bodies I aregrasped by an insulating-body conveying device 24 extending over theentire length of the production channel 2 and are fed to the downstreamprocessing stations in steps synchronously with the grid meshes M, M'.

Within the scope of the invention, it is possible to feed aninsulating-body sheet K to the delivery device 21 instead of theindividual insulating bodies I previously cut to length and to severinsulating bodies I of predetermined length from the sheet by means ofan insulating-body cutting device 25 arranged in the exit region of theguide device 22.

On both sides of the production channel 2, the lead devices 14, 14' areeach followed by a web-wire feeding and cutting device 26; 26', by meansof which a plurality of wires D, D' are simultaneously drawn off insteps from both sides of the production channel 2 from wire-supply reels27, 27' in the direction of the arrows P6, P6', are straightened in eachcase by means of a dressing device 28, 28', are introduced in thehorizontal direction into the interspace between the two grid meshes M,M' and are pushed through the insulating body I and severed from thewire supply.

It is possible, within the scope of the invention, to arrange all theweb-wire feeding and cutting devices 26, 26' successively in theproduction direction on one side of the production channel 2.

The insulating body I is pierced by a plurality of rows R1 and R2 eachof a plurality of straight web wires S arranged one above the other inthe vertical direction with a mutual spacing. The web wires S bear withtheir two ends in each case against the corresponding longitudinal wiresL, L' of the two grid meshes M, M' and protrude slightly laterallybeyond the grid meshes M, M', in order to guarantee reliable welding tothe corresponding longitudinal wires L, L' of the grid meshes. In theexemplary embodiment illustrated, the web wires S within a vertical rowR1 or R2 extend horizontally in the same direction obliquely relative tothe grid meshes M, M'. In adjacent rows R1, R2, the web wires extend atan inclination in the opposite direction. Within the scope of theinvention, it is also possible for the direction of the web wires to bethe same in all the rows. As seen in the horizontal direction, the webwires S extend in the form of horizontal lines Z obliquely betweenopposite longitudinal wires L and L' of the grid meshes M and M'. Therespective angles of the web wires S relative to the longitudinal wiresL, L' are selectable, the direction of the web wires S within a line Zchanging, so that a lattice work-like, zigzag-shaped arrangement of theweb wires S within a line Z is obtained. In the insulating body I,therefore, a plurality of parallel horizontal lines Z of web wires S arearranged one above the other in the vertical direction, that is to saythe web wires S form in the insulating body I, and consequently also inthe building element B to be produced, a matrix-like structure withhorizontal lines Z and vertical rows R1, R2.

The shoot-in angle, at which the web wires S are introduced into theinterspace between the two grid meshes M, M', can be adjusted bypivoting the web-wire feeding and cutting devices 26, 26' according tothe double arrows P7, P7'. The material and design of the insulatingbodies I must be such that, during the subsequent further transporttaking place in the production direction P4, the insulating bodies fixthe web wires S immovably in their position within the insulating body.The number, the shoot-in angles and the mutual vertical spacings of theweb wires S, arranged one above the other in the vertical direction in arow R1 or R2, as well as the horizontal spacing of the rows of web wiresare selected in conformity with the static requirements placed on thebuilding element B.

In many instances of use, it may be necessary to produce the insulatingbody I of the building element B from such hard materials that it cannotbe pierced by the web wires S without the latter being deformed. It ispossible, in this case, to use, for example, hard plastics, such aspolyurethane, lightweight concrete provided with expanded or foamablepolystyrene as a lightweight additive, plasterboards or cement-boundhardboards which contain plastic waste, wood shavings or wood chips,mineral or vegetable fibrous materials. Moreover, it is possible, withinthe scope of the invention, to construct the insulating body I inlayers, and the outer covering faces of the insulating body can consistof relatively hard materials impenetrable by the web wires, such as, forexample, hard plastic or wood boards, wood, jute, cane or bambooplaiting, and the core of the insulating body I of loose soft fillingmaterial, such as, for example, foam, plastic waste, wood wool ormineral wool. In these cases, each web-wire feeding and cutting device,26, 26' is preceded by a bradawl device 29, 29' shown diagrammaticallyin FIG. 1. Each bradawl device 29, 29' has a plurality of tools whichare arranged one above the other in the vertical direction and whicheach serve for shaping out a channel in the insulating body I forreceiving a web wire S in each case and are arranged on a commonpivotable column. At the same time, the columns of the bradawl devices29, 29' are fixedly coupled to the associated web-wire feeding andcutting device 26, 26' and, jointly with the latter, are movable in thedirection of the insulating body I of the building element B and awayfrom this and, jointly with the latter, are pivotable according to thedouble arrow P7, P7'.

It is possible, within the scope of the invention, to design the bradawldevices 29, 29' in conformity with the device described in EP-B-398,465.In this, the advancing movement of the bradawl devices 29, 29' forshaping out the receiving channel for the web wires takes placeindependently of the advancing movement of the web-wire feeding andcutting devices 26, 26'. Only the pivoting movement of each column ofthe bradawl devices 29, 29' for varying the shoot-in angles of the webwires S takes place synchronously with the pivoting movement of therespective associated web-wire feeding and cutting device 26, 26'according to the double arrows P7, P7'.

The tools for shaping out the receiving channel for the web wires S canbe designed as solid pricking needles or hollow needles or also asrotating gimlets and have a wear-resistant, for example hardened tip.The pricking needles or hollow needles can preferably be preheated intheir tips, in order to make it easier to pierce the insulating body I.

The two grid meshes M, M' are fed by means of the second pair ofadvancing elements 20, 20' of the grid-mesh conveying device 18 insteps, synchronously with the insulating body I together with the webwires S which is advanced by means of the insulating-body conveyingdevice 24, to downstream web-wire welding devices 30, 30', in which theweb wires S are welded in each case at one end to the longitudinal wiresL, L' of the grid meshes by means of welding tongs 31, 31'.

The now dimensionally stable building element B is conveyed further insteps by a downstream building-element conveying device 32 which hasessentially two pairs of conveying elements 33, 33' and 34, 34' locatedopposite one another on both sides of the production channel 2.

The projecting lengths E of the web wires S protruding laterally beyondthe grid meshes M, M' constitute a considerable risk of injury duringthe handling of the building element B, obstruct the stacking of thebuilding elements for transport and therefore have to be separated, sothat the wires terminate as flush as possible with the longitudinalwires L, L'. By means of the first pair of conveying elements 33, 33',the building element B is fed to downstream triming devices 35, 35'which are arranged offset on opposite sides of the production channel 2and which cut off the web-wire ends E, projecting laterally beyond thecorresponding longitudinal wires L, L' of the grid mesh M, M', flushwith the longitudinal wires L, L'.

Within the scope of the invention, it is possible to divide the finishedtriced building element B in the horizontal direction into at least twobuilding elements, preferably of the same size, by means of cuttingdevices 36, 36' downstream of the trimming devices 35, 35' on both sidesof the production channel 2. The cutting devices 36, 36' are designed insuch a way that they can sever both the transverse wires Q, Q' of thegrid meshes M, M' and the insulating body I.

It is also possible, within the scope of the invention, by means of thedelivery device 21, to feed individual insulating bodies I cut to lengthand/or a plurality of vertically extending endless insulating-bodysheets K to the guide device 22 in a plurality of tracks extending oneabove the other in the vertical direction.

Furthermore, it is possible, within the scope of the invention, todivide the one-piece insulating body I and/or the endless insulatingbody sheet K in the insulating-body cutting device 25, by means of anadditional cutting tool, into at least two portions or part sheetsextending one above the other in the vertical direction, so that onlythe transverse wires Q, Q' of the grid meshes M, M' still have to besevered in the cutting devices 36, 36'.

Moreover, according to the invention, it is possible in theinsulating-body cutting device 25, during the horizontal cutting of theinsulating body I or the insulating-body sheet K, not to sever thiscompletely, but only to cut into it from both sides or even only fromone side of the insulating body I of the insulating-body sheet K, suchthat a web connecting the two parts remains in the insulating body I. Inthis case, only the transverse wires Q, Q' of the grid meshes M, M' aresevered in the cutting devices 36, 36' and the final division of thefinished building element B into two or more building-element parts iscarried out only on site by breaking open the insulating-body web.

In order to keep the projecting length of transverse wire as small aspossible during the severance of the building element B and to avoid afurther trimming of the building-element parts, within the scope of theinvention it is possible, as shown in FIG. 2, to select the spacings ofthe two central longitudinal wires C, C' between which the buildingelement B is severed, correspondingly smaller than the remaininglongitudinal-wire division of the grid meshes M, M'.

The finished trimmed building element B is conveyed out of theproduction channel 2 by means of the second pair of conveying elements34, 34' of the building-element conveying device 32 and is transferredto devices (not shown) for transporting away or for stacking a pluralityof building elements.

The spacing between the second pair of advancing elements 20, 20' of thegrid-mesh conveying device 18 and the first pair of conveying elements33, 33' of the building-element conveying device 32 as well as thespacing between the pairs of conveying elements 33, 33' and 34, 34' mustalways be smaller than the smallest length of the grid meshes M, M' usedfor producing the building element B, in order to guarantee a reliablefurther conveyance of the grid meshes between the grid-mesh conveyingdevice 18 and the building-element conveying device 32 as well asthrough these.

For the continuous production of the building elements B, it isabsolutely necessary to feed the two grid sheets G, G', the grid meshesM, M' and the insulating-body sheet K or individual insulating bodies Ito the individual processing stations 11, 11'; 25; 26, 26'; 29, 29'; 30,30'; 35, 35'; 36, 36' reliably and in a fault-free manner. In order toguarantee this, the grid-sheet push-in devices 10, 10', the pairs ofadvancing elements 19, 19'; 20, 20' of the grid-mesh conveying device18, the pairs of conveying elements 33, 33'; 34, 34' of thebuilding-element conveying device 32 and the insulating-body conveyingdevice 24 are driven by a central main advancing drive 37, all theelements 19, 19'; 20, 20'; 33, 33'; 34, 34' end the grid-sheet push-indevices 10, 10' being connected to one another by means of articulateddrive shafts 38, 38'. The advancing steps take place intermittently,because the introduction of the web wires S, the welding of the webwires S to the wires of the grid mesh M, M' and the trimming of theweb-wire end parts each take place when the grid meshes, the insulatingbody or the building elements are stationary. At the same time, thelength of the advancing steps is selectable according to thetransverse-wire division or to an integral multiple of thetransverse-wire division.

Building elements B having a different predetermined width can beproduced by widening the production channel 2 and by a correspondingindividual or joint lateral adjustment of the advancing elements 19,19'; 20, 20', of the conveying elements 33, 33'; 34, 34' and of theelements of the processing stations 25; 26, 26'; 29, 29'; 30, 30'; 35,35'; 36, 36'.

The insulating-body conveying device 24 shown diagrammatically in FIG. 2has a conveyor chain 39 which is driven by the main advancing drive 37in the direction of the arrow P8 and which defines the conveying trackof the insulating bodies I within the production channel 2. The conveyorchain 39 carries a plurality of take-up carriers 40 which are eachprovided with a take-up dog 41. The take-up dogs 41 are made angular,hook-shaped or peg-like, in order to make a reliable connection to theunderside of the insulating body I and therefore, during the advance ofthe insulating body, prevent any slip between the latter and the take-upcarriers 40.

If the insulating bodies I are being fed in a plurality of trackslocated one above the other, the insulating-body conveying device 24 hasa further upper conveyor chain 39' with corresponding take-up carriers40' and take-up dogs 41' which engage on the top side of the insulatingbody I of the uppermost insulating-body sheet.

The advancing elements 19, 20 of the grid-mesh conveying device 18,which are shown diagrammatically in FIG. 2, have a shaft 42 which isinclined relative to the vertical and which is driven by an angular gear44 via a coupling 43 and is mounted in a counterbearing 45. The angulargear 44 is driven by the main advancing drive 37 (FIG. 1) via the driveshaft 38. Each shaft 42 is provided with a plurality of transport discs46 which are arranged at a mutual adjustable spacing and which arerotatable for adjustment on the shaft 42 and, after adjustment, arefixedly connected to the shaft 42 by means of a clamping element 47.

As shown in FIG. 3a, the transport discs 46 have a plurality ofgrid-engagement recesses 48 of selectable depth which are distributedregularly over the circumference, so that flattened teeth 49 areobtained. The number of grid-engagement recesses 48 is selectedaccording to the transverse-wire division of the grid meshes M, M', insuch a way that the transverse wires Q, Q' of the grid meshes aregrasped reliably by the transport discs 46 and the slip-free advance ofthe grid meshes is guaranteed. As a result of the inclination of theshafts 42, the transport discs 46 of each advancing element 19, 19'; 20,20' engage not only on one, but on a plurality of transverse wires Q, Q'of the grid meshes M, M', so that the tensile force is distributed to aplurality of wires and consequently these are not loaded excessivelyduring the advance of the grid meshes. Moreover, the inclination of theshaft 42 guarantees a continuous and slip-free further transport of thegrid meshes M, M' of successive building elements B, and in the joiningregion the successive grid meshes can have spacings which are obtained,for example, during the trimming of the grid meshes or during theseparation of portions from the grid sheets G, G'.

The conveying elements 33, 33'; 34, 34' of the building-elementconveying device 32 are designed in a similar way to the advancingelements 19, 19'; 20, 20' of the grid-mesh conveying device 18. Only thetransport discs 46 have grid-engagement recesses 48 of smaller depth.The grid-sheet push-in devices 10, 10' have essentially the sameelements as the advancing elements 19, 20 of the grid-mesh conveyingdevice 18 which are shown in FIG. 2. The only difference is that, asshown in FIG. 3b, the grid-engagement recesses 48 of the transport discs50 are substantially deeper, so that they have pointed teeth 51. Thisshaping of the teeth 51 ensures that the teeth 51 engaging from the sideinto the non-guided grid sheet G, G' grasps the transverse wires Q ofthe grid sheets G, G' reliably and advance the grid sheets G, G' in aslip-free manner.

The web-wire welding devices 30, 30' shown diagrammatically in FIGS. 4and 5 are located offset opposite one another on the outside of the twogrid meshes M and M'. Each web-wire welding device, 30, 30' has a mount52 which consists essentially of a bottom plate 53, of a cover plate 54and of a vertical angle plate 55. The mount 52 is adjustable accordingto the double arrow P9 in the vertical direction, according to thedouble arrow P10 in the horizontal direction perpendicular to the gridmeshes M, M' and according to the double arrow P11 in the horizontaldirection parallel to the grid meshes. At the same time, the bottomplate 53 and the cover plate 54 are each mounted so as to be verticallyand horizontally displaceable in a baseplate 57 by means of an adjustingdevice 56. The vertical adjustment according to the double arrow P9takes place, for example, by means of an adjusting thread, whilst thehorizontal adjustment perpendicular to the grid meshes M, M' accordingto the double arrow P10 is carried out, for example, by an eccentricadjusting device. Each baseplate 57 is mounted so as to be displaceableaccording to the double arrow P11 parallel to the grid meshes M, M' on afixed basic frame 59 provided with a dovetail guide 58.

The bottom plate 53 is equipped with two lower bearing cheeks 60, inwhich a lower eccentric shaft 61 is mounted rotatably. The coverplate 54has two upper bearing cheeks 62, in which an upper eccentric shaft 63 ismounted rotatably. The pivoting movement of the lower eccentric shaft 61takes place by means of a drive element, for example a working cylinder,and of a pivoting lever fixedly connected to the lower eccentric shaft61. By means of a coupling element, for example a coupling rod, betweenthe lower eccentric shaft 61 and the upper eccentric shaft 63, thepivoting movement of the lower eccentric shaft 61 is transmitted to theupper eccentric shaft 63 in such a way that the upper eccentric shaft 63executes a simultaneous, but opposed pivoting movement. A frontvertically extending welding-tong bar 64 and a rear vertically extendingwelding-tong bar 65 are pivotably mounted, in each case via plainbearings or via fixed bearings, in the eccentric part 61' of the lowereccentric shaft 61 and in the eccentric part 63' of the upper eccentricshaft 63. The front welding-tong bar 64 carries a plurality of two-armedlower welding-tong levers 66 arranged at a mutual vertical spacing, andthe rear welding-tong bar 65 carries a plurality of two-armed upperwelding-tong levers 67 arranged at a mutual vertical spacing, eachwelding-tong lever 66 or 67 being mounted pivotably in a welding-tongbearing 68 according to the double arrow P12 and in an electricallyinsulated manner. The number of upper and lower welding-tong levers 66and 67 corresponds at least to the number of web wires S within avertical row of web wires R1 and R2. Each welding-tong lever 66 or 67has, at its front end facing the grid meshes M, M', a welding electrode69 and, at its other end, is supported via a spring element 70 in eachcase on a support plate 71 extending obliquely, the correspondingsupport plates 71 each being arranged on a vertical supporting bar 72fixedly connected to the corresponding welding-tong bars 64; 65. Thespring force and spring excursion of each spring element 70 areindividually adjustable, in order to generate the necessary weldingpressure and to allow the resetting of the welding electrode 69 which isnecessary during the welding operation as a result of the softening ofthe wires S; L, L'. All the support plates 71 are electrically insulatedfrom one another by means of insulating pieces 73. As shown in FIG. 5,two welding electrodes 69 can be arranged on each welding-tong lever 66or 67, so that two web wires S are simultaneously welded to alongitudinal wire L or L'. The upper and lower welding-tong levers 66and 67 cooperate respectively in pairs and form the jaws of the weldingtongs 31 and 31', the welding electrodes 69 of each pair of weldingtongs 31 and 31' being located congruently one above the other in thewelding position. The mutual vertical spacing of the welding electrode69 in the welding position corresponds to the vertical spacing of theweb wires S within the rows of web wires R1 and R2. All the welding-tonglevers 66 and 67 are electrically connected to the associatedwelding-tong bars 64 and 65 by means of flexible current leads.

Each welding-tong bar 64 and 65 is connected in each case via twoflexible current strands 74 to the two secondary terminals 75 of awelding transformer 76, all the electrical parts being covered in amanner protected against accidental contact by means of a covering 77.However, within the scope of the invention, it is also possible, in thecase of a lower power requirement, to use only one welding transformerfor both welding-tong bars.

The welding device works as follows:

As a result of the rotational movement of the lower eccentric shaft 61and as a result of the opposed rotational movement of the uppereccentric shaft 63 taking place simultaneously by virtue of the couplingelement, the front welding-tong bar 64 pivots according to the doublearrow P13 and the rear welding-tong bar 65 pivots in the oppositedirection according to the double arrow P14 out of their initialposition into the welding position and, after welding has terminated,back into the initial position again. The left-hand half of the drawingin FIG. 4 shows the welding-tong levers 66 and 67 in their initialposition and the right-hand half of the drawing in FIG. 4 shows them intheir welding position. In the welding position, at least the weldingelectrodes 69 reach into the grid-mesh plane, that is to say into thegrid apertures, formed by adjacent longitudinal and transverse wires, ofthe grid meshes M, M', in order to grasp over a large area both the webwire S to be welded and the associated longitudinal wire L; L' of therespective grid mesh. In the initial position, the welding electrodes 69are located outside the grid-mesh planes, so as not to obstruct theadvance of the building element B.

The trimming devices 35 and 35' shown diagrammatically in FIGS. 6 and 7each have a mount 78 which consists essentially of two vertical carrierplates 79 and which is provided with two bearing journals 80. The mount78 is adjustable according to the double arrow P15 in the verticaldirection, according to the double arrow P16 in the horizontal directionperpendicular to the side faces of the building element B and accordingto the double arrow P17 in the horizontal direction parallel to the sidefaces of the building element B.

The vertical adjustment of the mount 78 takes place by means of anadjusting thread in the bearing journals 80. Each bearing journal 80 ismounted eccentrically in a one-armed approach lever 81 which is itselfmounted pivotably in a base plate 82. As a result of the pivoting of theapproach lever 81, for example by means of an adjusting spindle, thehorizontal adjustment of the mount 78 perpendicular to the grid meshesM, M' of the building element B according to the double arrow P16 takesplace. Each base plate 82 is mounted so as to be displaceable accordingto the double arrow P17 parallel to the grid meshes M, M' on a basicframe 84 provided with a dovetail guide 83.

A lower eccentric shaft 85 and an upper eccentric shaft 86 are mountedrotatably in the two carrier plates 79, the pivoting movement of thelower eccentric shaft 85 taking place by means of a drive element, forexample a working cylinder, and of a pivoting lever connected fixedly tothe lower eccentric shaft 85. By means of a coupling element, forexample, a coupling rod, connecting the lower eccentric shaft 85 to theupper eccentric shaft 86, the pivoting movement of the lower eccentricshaft 85 is transmitted to the upper eccentric shaft 86 in such a waythat the upper eccentric shaft 86 executes a simultaneous, but opposedpivoting movement.

In the eccentric part 85' of the lower eccentric shaft 85 and in theeccentric part 86' of the upper eccentric shaft 86, two verticallyextending cutting bars 87 arranged at a mutual spacing are mountedpivotably, in each case via fixed bearings and via plain bearings, and aknife bar 88 extending between the two cutting bars 87 is mountedpivotably, in each case via plain bearings or via fixed bearings. Thecutting bars 87 jointly carry, on their sides facing the buildingelement B, a row of upper knives 89 arranged one above the other at anadjustable mutual spacing, and the knife bar 88 carries, on its sidefacing the building element B, a row of lower knives 90 arranged oneabove the other at an adjustable mutual spacing.

The number of upper knives 89 and of lower knives 90 corresponds atleast to the number of lines Z of web wires to be trimmed. The mutualspacing of the upper knives 89 and of the lower knives 90 relative toone another corresponds to the spacing of the lines Z of web wires to betrimmed. As a result of the coupled pivoting movements of the twoeccentric shafts 85 and 86, the cutting bars 87 execute a pivotingmovement according to the double arrow P18 and the knife bar 88 executesan opposed pivoting movement according to the double arrow P19.

FIG. 6 shows the trimming device 35' in the initial position and thetrimming device 35 in the working position. The trimming devices 35, 35'work as follows: As a result of the rotational movement of the lowereccentric shaft 85 and as a result of the opposed rotational movement ofthe upper eccentric shaft 86 taking place simultaneously by virtue ofthe coupling element, the cutting bars 87 pivot according to the doublearrow P18 and the knife bar 88 pivots in the opposite directionaccording to the double arrow P19 out of their initial position into thecutting position and, after the projecting lengths E of web wire havebeen severed, back into the initial position again.

It is also possible, within the scope of the invention, to mount thecutting bars 87 and the knife bar 88 in each case on two separateeccentric shafts and to pivot the cutting bars 87 and the knife bar 88in each case separately by means of a working cylinder acting on therespective eccentric shaft. At the same time, the pivoting movement ofthe knife bar 88 takes place independently of the pivoting movement ofthe cutting bars 87, in each case in the opposite direction to thepivoting movement of the cutting bars 87.

Furthermore, within the scope of the invention, it is possible to designthe upper knives 89 and lower knives 90 and activate the cutting bars 87having the upper knives 89 and the knife bar 88 having the lower knives90 in such a way that, during the cutting operation, each upper knife 89serves as an abutment for fixing the longitudinal wire L, L', to whichthe web wire S to be trimmed is welded, whilst the associated lowerknife 90 acts as a cutting tool for severing the projecting length E ofweb wire and shears off the projecting length E of web wire in thedirection of the longitudinal wire L, L' retained by the upper knife 89.

The cycles of movement of the welding-tong bars 64, 65 of the web-wirewelding device 30, 30' as well as of the cutting bars 87 and knife bar88 of the trimming devices 33, 35' must be coordinated exactly with oneanother, in order, on the one hand, not to deform the longitudinal wiresL, L' of the grid meshes M, M' or the building element B during thewelding of the web wires S to the longitudinal wires L, L' and duringthe trimming of the web wires S and, on the other hand, to positioncorrectly the welding tongs 31, 31' or the upper and lower knives 89; 90for welding the web wires S to the longitudinal wires L, L' or forsevering the projecting lengths E of web wire. For this reason, thereare automatic measuring and control devices (not shown) which monitorand control the individual equipment of the web-wire welding devices 30,30' and of the trimming devices 35, 35' and their cycles of movement.

In order to increase the productivity of the plant and avoidinterrupting the continuous production flow, a further exemplaryembodiment of a plant according to the invention, as shown in a partialtop view in FIG. 8, has, in each case, two supply reels 91, 91' and 92,92' for grid sheets G1, G1' and G2, G2', grid sheets G1, G1' or G2, G2'being fed in the direction of the arrows P20, P20' and P21, P21' fromone pair of associated supply reels 91, 91' or 92, 92' to the downstreammesh shears 11, 11', whilst the other pair of associated supply reels92, 92' or 91, 91' in readiness. Each supply reel 91, 91' or 92, 92' isfollowed by grid-sheet guides 93, 93' and 94, 94' and by straighteningdevices 95, 95' and 96, 96'. Each straightening device 95, 95' and 96,96' has a feed device 97, 97' and 98, 98', in each case with a drivingroller 99, 99' and 100, 100' pivotable according to the double arrowsP22, P22' and P23, P23'. In this exemplary embodiment, the grid-sheetpush-in devices 10, 10' must have a pivoting range which can cover bothgrid sheets G1, G1' and G2, G2'.

It goes without saying that the exemplary embodiments described can bevariously modified within the scope of the general inventive idea, andin particular the two grid meshes M, M' can have a different design,that is to say different longitudinal-wire divisions and/ortransverse-wire divisions as well as different diameters of thelongitudinal wires and/or transverse wires. However, the varioustransverse-wire divisions must correspond to integral multiples and canamount, for example to 50, 100, 150 mm. A further restriction is that itis necessary to guarantee that the web wires S can be positioned in sucha way that, despite these different wire divisions and wire diameters,they can be welded reliably to the longitudinal wires of the two gridmeshes M, M'.

Within the scope of the invention, it is possible to feed grid meshes M,M' already cut to length to the push-devices 10, 10' instead of the gridsheets G, G'; G1, G1'; G2, G2', in this case the mesh shears 11, 11'being inoperative.

It is possible, furthermore, to produce building elements B, in whichone and/or both grid meshes M, M' project beyond the insulating body Ion one side or on both sides extending parallel to the productiondirection P4. In order to achieve this, either the take-up dogs 41 areraised or lengthened, or the conveying track of the conveyor chain 39 israised, in such a way that the lower side face, extending parallel tothe production direction P4, of the insulating body I is raisedcorrespondingly, with the result that one and/or both grid meshes formthe desired projecting length on this side.

The conveying track of the upper conveyor chain 39' arranged on the topside of the insulating bodies I must be lowered correspondingly or thetake-up dogs 41' lowered or lengthened correspondingly.

To produce building elements B, in which the insulating bodies I projectbeyond the two grid meshes M, M' on one side or on both sides extendingparallel to the production direction P4, the conveying track of thelower conveyor chain 39 is lowered and, if appropriate, the conveyingtrack of the upper conveyor chain 39' raised, in such a way that thelower And, if appropriate, the upper side face, extending parallel tothe production direction P4, of the insulating body I is lowered orraised correspondingly, with the result that the insulating body Iprojects beyond the two grid meshes M, M' with the desired projectinglengths on one or on both sides.

The continuous production of the building elements B by means of theplant according to the invention preferably takes place in such a waythat the grid meshes M, M' of successive building elements B areseparated from one another only by a negligibly narrow separating gapbetween the longitudinal wires of successive grid meshes M, M' and alsothe correspondingly associated insulating bodies I of successivebuilding elements B follow one another without appreciable gaps.

Within the scope of the invention, however, it is also possible toproduce building elements B, in which one and/or both grid meshes M, M'project beyond the insulating body I on one or on both sides extendingperpendicularly to the production direction P4. If one or both gridmeshes M, M' are to project beyond the insulating body I on both sides,the insulating bodies I of adjacent building elements B are fed to theproduction channel 2 at correspondingly selected spacings by thedelivery device 21 and are advanced there with these mutual spacings. Ifan endless insulating-bodysheet K is used, a portion corresponding tothis spacing must be separated from the sheet K when the insulatingbodies I are being severed. The two separating gaps between the gridmeshes M, M' of successive building elements B are located eitherexactly opposite one another or are offset laterally to one another.

To produce building elements B, in which the insulating bodies I projectbeyond the two grid meshes M, M' on one or on both sides extendingperpendicularly to the production direction P4, the grid meshes areadvanced at predetermined spacing in the production channel 2. Toproduce this selectable spacing between the grid meshes M, M' ofsuccessive building elements B, a portion corresponding to this spacingis cut out from the endless grid sheets G, G' by the mesh shears 11, 11'while the grid meshes are being made. The size of the spacing is limitedby the need to ensure that the gaps between the grid meshes M, M' ofsuccessive building elements B can be bridged by the inclined shafts 42of the grid-mesh conveying device 18 and of the building-elementconveying device 32, in order to guarantee a slip-free advance of thegrid meshes of successive building elements B.

Within the scope of the invention, in the case of large spacings betweenadjacent rows of web wires R1 and R2, two or more web-wire weldingdevices 30 and 30' for each side face can also be arranged insuccession, as seen in the direction of advance P4 of the grid meshes M,M'. At the same time, the welding-tong levers 66 and 67 and the weldingelectrode 69 are designed in such a way that only one web wire S iswelded to a corresponding longitudinal wire L, L' by each pair ofwelding tongs 31, 31'.

In order to increase the production speed, moreover, within the scope ofthe invention a plurality of trimming devices can be arranged insuccession in the horizontal direction on each side face of the buildingelement.

We claim:
 1. Plant for the continuous production of building elementswhich consist of two parallel flat grid meshes made from intersectinglongitudinal and transverse wires welded to one another at theintersection points, of straight web wires holding the grid meshes at apredetermined mutual spacing and of an insulating body which is arrangedbetween the grid meshes and through which the web wires penetrate, witha production channel, with two supply reels, arranged on both sides ofthe production channel, and downstream straightening devices, each for agrid sheet, with two curved lead devices opening tangentially onopposite longitudinal sides of the production channel, with aninsulating-body guide device arranged between the two lead devices, withat least one group, arranged laterally of the production channel, ofweb-wire supply reels and web-wire feeding and cutting devices, withweb-wire welding devices which are arranged on both sides of theproduction channel and which have a transformer and flexible electricalleads from the secondary outputs of the transformer to jaws of weldingtongs pivotable into the grid-mesh planes, and with web-wire trimmingdevices, each for severing a projecting length of web wire,characterized in that a push-in device (7, 7') for drawing off in stepsan endless grid sheet (G, G'; G1, G1'; G2, G2') standing on edge from atleast one supply reel (3, 3'; 91, 91'; 92, 92') and for introducing thegrid sheet into the lead devices (14, 14') is arranged on each of thetwo sides of the production channel (2), in that two cutting devices(11, 11') for severing grid meshes (M, M') of predetermined length fromthe endless grid sheets (G, G'; G1, G1'; G2, G2') are provided upstreamof the lead devices (14, 14'), the grid meshes (M, M') being capable ofbeing advanced in steps in the lead devices (14, 14') and in theproduction channel (2) by means of a grid-mesh conveying device (18), inthat an insulating-body conveying device (24) extending over theinsulating-body guide device (22) and the production channel (2) isprovided for advancing in steps, synchronously with the grid meshes (M,M'), at least partially dimensionally stable insulating bodies (I)intended for fixing the web wires (S), in that the feeding and cuttingdevices (36, 36') for equipping the insulating body (I) with web wires(S) and downstream welding devices (29, 29') for the simultaneouswelding of the two ends of all the web wires (S) to correspondinglongitudinal wires (L, L') of the grid meshes (M, M') are provided inthe effective range of the grid-mesh conveying device (18), in that, bymeans of a building-element conveying device (32), the building elements(B) can in steps and successively be fed to the web-wire trimmingdevices (35, 35') and be conveyed out of the production channel (2), andin that the push-in devices (7, 7') and all the conveying devices (18,24, 32), coupled to one another, can be driven jointly by means of driveshafts (38, 38').
 2. Plant according to claim 1, characterized in thatthe length of the advancing steps of the grid-sheet push-in devices (10,10'), of the grid-mesh conveying device (18), of the building-elementconveying device (32) and of the insulating-body conveying device (24)corresponds to the smallest spacing of the transverse wires (Q, Q') ofthe grid meshes (M, M') or to an integral multiple of this spacing. 3.Plant according to claim 1, characterized in that the grid-sheet push-indevice (10, 10'), the grid-mesh conveying device (18), thebuilding-element conveying device (32) and the insulating-body conveyingdevice (24) can be driven synchronously by a joint main advancing drive(37).
 4. Plant according to claim 1, characterized in that a deliverydevice (21) is provided for the at least single-track feed of insulatingbodies (I) cut to length and/or of an endless insulating-body sheet (K)into the guide device (22) and, in the exit region of the guide device(22), a cutting device (25) is provided for severing insulating bodies(I) of predetermined length from the insulating-body sheet (K).
 5. Plantaccording to claim 1, characterized in that the insulating bodies (I)and/or the grid meshes (M, M') of successive building elements (B) canbe advanced with predetermined spacings along the production channel(2), the insulating bodies (I) being capable of being introduced withpredetermined spacing into the production channel (2) by means of adelivery device (21) or portions of predetermined length capable ofbeing separated from the insulating-body sheet (K) by means of thecutting device (25) during the severance of the insulating bodies (I),and in that portions of predetermined length can be cut out from thegrid sheets (G, G'; G1, G1'; G2, G2') by means of the cutting devices(11, 11') while the grid meshes (M, M') are being severed from theendless grid sheets (G, G'; G1, G1'; G2, G2').
 6. Plant according toclaim 1, characterized in that the grid-mesh conveying devices (18) andthe building-element conveying device (31) each have at least two pairsof advancing elements (19, 19'; 20, 20') or conveying elements (33, 33';34, 34'), the individual elements of all the pairs being locatedopposite one another on both sides of the production channel (2). 7.Plant according to claim 6, characterized in that each advancing element(19, 19'; 20, 20'), each conveying element (33, 33'; 34, 34') and eachgrid-sheet push-in device (10, 10') has a shaft (42) inclined relativeto the vertical direction and having at least two transport discs (46,50) provided with a plurality of grid-engagement recesses (48).
 8. Plantaccording to claim 3, characterized in that the insulating-bodyconveying device (24) has at least one conveyor chain (39, 39') whichcan be driven by the main advancing drive (37) and extends over theentire length of the production channel (2) and which has a plurality oftake-up dogs (41, 41').
 9. Plant according to claim 8, characterized inthat the conveying track of the conveyor chain (39, 39') or the take-updogs (41, 41') can be raised and lowered.
 10. Plant according to claim1, characterized in that the grid-sheet push-in devices (10, 10') arepivotable into the advancing track of the grid sheets (G, G'; G1, G1';G2, G2').
 11. Plant according to claim 1, characterized in that thestraightening devices (5, 5'; 95, 95'; 96, 96') each have a grid-sheetfeed device (7, 7'; 97, 97'; 98, 98') with a driving roller (9, 9'; 99,99'; 100, 100') each driving roller being pivotable into the advancingtracks of the grid sheets (G, G'; G1, G1'; G2, G2').
 12. Plant accordingto claim 1, characterized in that the web-wire feeding and cuttingdevices (26, 26') are pivotable in order to vary the shoot-in angles ofthe web wires (S).
 13. Plant according to claim 1, characterized in thata web-wire feeding and cutting device (26, 26') is arranged on each ofthe two sides of the production channel (2).
 14. Plant according toclaim 1, characterized in that each web-wire feeding and cutting device(26, 26') is preceded by a bradawl device (29, 29') for shaping channelsin the insulating body (I) for receiving web wires (S), these bradawldevices (29, 29') being movable in the direction of the insulating body(I) and away from this and being pivotable synchronously with theweb-wire feeding and cutting devices (26, 26') in order to vary theshoot-in angles of the web wires (S).
 15. Plant according to claim 14,characterized in that the bradawl devices (29, 29') for forming thereceiving channel have a pricking tool with a heatable tip.
 16. Plantaccording to claim 1, characterized in that, for each side face of thebuilding element (B) to be produced, at least one welding device (30,30') provided with a plurality of welding tongs (31, 31') is providedfor simultaneously welding, in each case, one end of a plurality ofstraight web wires (S), arranged one above the other at a mutual spacingin at least one row (R1, R2), to the horizontally extending longitudinalwires (L, L') of a grid mesh (M; M'), the welding tongs (31, 31') beingdesigned as two-armed pivotable lower and upper welding-tong levers (66;67) which cooperate in pairs and of which the ends facing the gridmeshes (M, M') and pivotable into the grid-mesh planes have weldingelectrodes (69) for welding at least one web wire (S) to a longitudinalwire (L; L') of the grid mesh (M; M').
 17. Plant according to claim 16,characterized in that all the lower welding-tong levers (66) arearranged on a pivotable vertical front welding-tong bar (64) and all theupper welding-tong levers (67) on a pivotable vertical rear welding-tongbar (65).
 18. Plant according to claim 17, characterized in that thefront welding-tong bar (64) and the rear welding-tong bar (65), drivenby a drive element and connected by means of a coupling element, arepivotable simultaneously, but in opposition.
 19. Plant according toclaim 17, characterized in that each welding-tong lever (66, 67) issupported on the associated welding-tong bar (64; 65) by means of aspring element (70) having an adjustable spring force and adjustablespring excursion.
 20. Plant according to claim 16, characterized in thateach welding device (30, 30') is adjustable perpendicularly and parallelrelative to the side faces of the building element (B).
 21. Plantaccording to claim 1, characterized in that at least one trimming device(35, 35') for simultaneously severing at least two adjacent projectinglengths (E) of web wire, which has at least one pivotable upper knife(39) and a pivotable lower knife (90) cooperating with the latter, isprovided for each side face of the building element (B).
 22. Plantaccording to claim 21, characterized in that an associated upper knife(89) and an associated lower knife (90) are provided for each horizontalline (Z) of web wires (S) which is provided in the building element (B).23. Plant according to claim 21, in that all the upper knives (89) of atrimming device (35, 35') are arranged on at least one pivotable cuttingbar (87) and 811 the lower knives (90) of a trimming device (35, 35')are arranged on a pivotable knife bar (88).
 24. Plant according to claim21, characterized in that the cutting bar (87) and the knife bar (88),driven by a drive element and connected by means of a coupling element,are pivotable simultaneously, but in opposition.
 25. Plant according toclaim 21, characterized in that 811 the upper knives (89) of a trimmingdevice (35, 35') are fastened on at least one cutting bar (87) pivotableby means of at least one drive element and all the lower knives (90) ofa trimming device (35, 35') are fastened on a knife bar (88) pivotableby means of at least one further drive element, the knife bar (88)executing a pivoting movement opposed to the pivoting movement of thecutting bar or cutting bars (87).
 26. Plant according to claim 25,characterized in that each upper knife (89) forms at the same time anabutment for the associated longitudinal wire (L, L') and is pivotablein its working position by means of the cutting bar or cutting bars (87)in order to fix the associated longitudinal wire (L, L'), and each lowerknife (90) can subsequently be actuated by means of the knife bar (88)in order to sever the projecting lengths (E) of web wire.
 27. Plantaccording to claim 21, characterized in that the cutting bar or cuttingbars (87) and the knife bar (88) of each trimming device (35, 35')extends in each case perpendicularly to the longitudinal wires (L, L')to which the web wires (S) are welded.
 28. Plant according to claim 21,characterized in that each trimming device (35, 35') can be adjustedperpendicularly and parallel relative to the side faces of the buildingelement (B).
 29. Plant according to claim 1, characterized in that thetrimming devices (35, 35') are followed, at least on one side of theproduction channel (2), by a cutting device (36, 36') for the horizontaldivision of the building element (B) into at least two portionspreferably of the same size.
 30. Plant according to claim 1,characterized in that the insulating-body cutting device (25) has atleast one cutting tool for severing the insulating body (I) and/or theendless insulating-body sheet (K) into at least two portions and/or partsheets arranged one above the other in the vertical direction.
 31. Plantaccording to claim 1, characterized in that, in order to adjust thewidth of the building element (B) to be produced, at least the devices(14', 15', 16', 17', 19', 20', 26', 29, 30', 33', 34', 35', 36', 38')arranged on one side of the production channel (2) are displaceablerelative to the devices (14, 15, 16, 17, 19, 20, 26, 29, 30, 33, 34, 35,36, 38) arranged on the other side of the production channel (2).